Glue-tester.



v E. S. SMITH.- GLUE TESTER. APPLIUATION FILED un. 7, 190s.

Patented Feb. 2, 1909.

fria/enfer'.

nl: Nonsls Eriks Co., wAsHINcrogv, D. c.

UTE

srA'rns PATENT muc EDMUND sEvvALL SMITH, or NIAGARA FALLS, NEW YORK.

GLUE-TE'STEB.

Specification of Letters Patent.

atented Feb. 2, 1909.

Application led. March 7, 1908. Serial No. 419,733.

nants possess the property of absorbing coldv water in quantity, whichsoftens them and causes them to swell. Tf these are heated, theydissolve in the absorbed water, from which solution they gelatinize orform a jelly after cooling. When this processis carried outwith-carefully measured amounts of glue and water, the strength `orconsistency of the jelly formed is a most important indication of thequality and binding power of the glue. The stronger-,the glue, thegreater will be the resistence oiered by its jelly to outside pressure.This fact is so well recognized in the trade that the so-called jellytest has come to be the one most relied upon to determine the relativevalue and adhesive power of glues. To Vmeasure vor compare the relativestiffness of these jellies, several methods are in use. The most commonone is the simple finger test. The glues are prepared in the usualmanner by taking carefully weighed amounts, soaking each in a definitequantity of water in a suitable vessel, usually an ordinary glasstumbler, heating same to about 150 degrees Fahrenheit, and allowing tocool. The relative consistency of the jellies is determined by pressingthe finger upon the surface of the jelly, the grading being done whollyby the sense of touch. Another method, the so-called shot test has forits object the determination of the weight the various jellies Varecapable of sustaining.

The apparatus consists essentially of a saucer-shaped disk of tin, theconvex side of which presses u oon the surface of the jelly. Weight, inthe orm of shot, isl applied until the saucer just penetrates, thejelly. The weight of the shot used is taken as an index of the strengthof the jelly. Still another method is based upon the time required byvrods of different weights to sink a fixed distance into the jelly. It isobvious that the presence of a skin on the surface of the jelly as wellas the friction produced-in both of these forms of apparatusbetweentheir moving parts and the jelly surface or jelly body introducefactors'which seriously interfere l Y with their accuracy, in fact,render the re- SEWALL- sults obtained kof very questionable value.

My invention relates to an improved device for measuring and comparingthe strength of these jellies wherein the defects of `the apparatus andmethods commonly used are eliminated andV by which I am enabled tomeasure much smallerdiiferences in strength than has heretofore beenpossible. Tn the accompanying drawing, the front elevation vof theapparatus is shown.

. The pressure chamber A consists of a glass bulb with an openmg on itslower face across which is fitted a thin elastic soft rubber diaphragmB. The chamber contains water which also extends up into the stem C,this stem being a glass'tube which connects the chamber A with the tubeD. The tube D is connected at one end'to the soft rubber bulb tainedfrom the scale L. Another scale, M,

is located behind the stem C. The glass con taining'the jelly is placedon the table J This is then raised by the hand screw K. When the jellysurface comes in contact with the diaphragm, the diaphragm and the waterabove it are forced upwards. The table is raised until the water in thestem C rises to a certain point on the scale M, stopcock H being open tothe atmosphere. This same point 1s used for all the jellies to betested, thus furnishing a measured and therefore, constantv degree ofcontact between the jelly surface and the elastic diaphragm B. Thestop-cock H is closed and G opened to connect the rubber bulb E withtube D. The bulb is then compressed. Its contained air exerts a pressureupon the water in both the stem C `and in the manometer F, F. Thepressure in C is communicated to the diaphragm B and, by its expansion,

'point stop-cock G is turned, closing o tube D. The height of the liquidn the manometer is then read on the scale L. The point thus obtained isa direct reading of the pressure upon the jelly surface. W hen thereading is secured, stop-cock H is openedvto the atmosphere thusarranging it tor subsequent tests.

In the drawing, the apparatus is shown as it appears when the reading ofthe manoineter is to be taken. The water in the stein has been forceddown to the lower point on scale lvl, the pressure upon the diaphragmhas distorted the jelly and the amount oi this pressure is shown on theinanoineter scale L.

inasmuch as the diaphragm is always forced a fixed distance into thejelly, this disturbance being measured by the travel of the water on thescale M, the pressure necessary to force it this distance varies withthe sti'n'ness ot' the jelly. Thus the pressure becomes an inderr of theconsistency of the jelly and this pressure is read directly upon themanometer scale. have found accurate results are obtained by high gradeglues by using l2 to l5 grams of dry glue to 100 cubic centimeters ofwater. W ith lower grade glues, higher percentages of glue are nec- Withmy apparatus, duplicate tests on the same glue sample may be made, asthe surface of the jelly is not broken, and these duplicate tests agreeidentically with the original. Using different amounts oit the sameglue, the apparatus will detect as small a Variation as one fourth ofone gram in the weight oi' dry glue taken. t will also measure jelliestoo soft to be touched by the finger.

do not limit my invention to apparatus for measuring the strength ot'glues and gelatins. lt is equally useful with Amany gelati* nous-likesubstances, for eXamplc:-starch,

gelese, agar-agar, Irish moss, Japanese of gelatinous substances,comprising a pressure chamber one side of which is provided with aflexible elastic diaphragm, means toi' bringing one 'free surface ot thegelatinous substance into contact with said diaphragm, means forgenerating pressure within said chamber thereby expanding the diaphragmand displacing the gelatinous substance, and means tor measuring suchpressure, substantially as described.

2. fin apparatus for measuring the strength of gelatinous substances,comprising a pressure chamber one side oi" which is provided with atlexible elastic diaphragm, means ior bringing one tree surface ol thegelatinous substance into contact with said diaphragm, means forgenerating pressure within said chamber thereby exjtianding thediaphragm and displacing the gelatinous substance, means of measuringthe amount of such displacement, and means t'or measuring said pressure,substantially as described.

an apparatus t'or measuring the strength of gelatinous substances7comprising the pressure chamber jr provided with the elustic diaphragmB, the adjustable holder d supporting the gelatinous substance, thepressure generator l and the nanometer tubes F, F, substantially asshown.

n testimony whereof, l have signed my name to this specification in thepresence ol" two subscribingv witnesses.

EDMUND SElVALL SBHTH. `Witnesses G. lV. MARLEY, A. D. Krson.

